There is the bait, and then, my friends, there is the switch. The premise of “Partners,” a new CBS sitcom, raises curiosity. From David Kohan and Max Mutchnick, the makers of the classic “Will & Grace,” the show is based on their own gay-straight friendship. While gay-straight relationships between men aren’t new to primetime — Adam Pally’s bonds with the straight men on “Happy Endings” are lovely — still they haven’t been zeroed in on quite this closely. I’m drawn to the idea of gay and straight men connecting on TV in a non-“Queer Eye for the Straight Guy” manner.

But what an irritating show! Almost every line is a bad joke! It’s like reading a series of sentences that all end in exclamation points! “Partners” is ham on a shtick, a broad sitcom that moves at the same Ritalin pace as “2 Broke Girls,” the vaudeville showcase that airs right after it. Every other gag on “Partners” is a double entendre about sexual activity or, in the words of one character, the “shmeckel,” and every funny one-liner is followed and preceded by three or four misses. Maybe five.

The characters, meanwhile, are an inch deep. Michael Urie, who was Marc on “Ugly Betty,” plays Louis, a gay man who is as fabulously narcissistic and superficial as they come. He’s like a hybrid of Jack and Karen from “Will & Grace.” David Krumholtz, from “Numb3rs,” is Joe, the menschy straight guy who tolerates Louis and his meddling, manipulative, self-serving ways. It’s so predictable: Louis, always dancing across the stage, tries to redecorate his best friend’s existence. In the language of “Queer Eye” he’s always attempting to tszuj (jooj) Joe’s life. And Joe, so rational, moans and groans like a stereotypical sitcom hubby, until eventually, aww, Louis makes everything right.

Louis and Joe are each involved in love affairs. Louis’s boyfriend is Wyatt, who is played as Louis’s polar opposite by Brandon Routh, the once and probably not future Superman. Wyatt is quiet, kind, and dense, a nurse who’s always thinking of others’ feelings. What is he doing with Louis? Best not to ask that question, because I suspect there is no believable answer. “I’m in the cardiac wing today,” Wyatt tells Joe, while pointing to a pin on his scrubs. “That’s why I’ve got a heart on. I can give you one if you want.” As he delivers his lines, Routh’s timing is either wonderfully offbeat or just totally off — it’s hard to tell in the first two episodes. Or should I say it’s not easy to tell.

Joe is involved with Ali (Sophia Bush), a jewelry designer who is willing to share Joe with Louis. The guys work together at their architecture firm, whose secretary, Ro-Ro (Tracy Vilar) is sassy and always ready to help Louis get through his latest drama by holding his head against her breasts. Monday night, Joe is thinking of proposing to Ali, and Louis quickly complicates the situation when he talks to Ali during their yoga class. Next week, Joe tells Louis that he and Ali haven’t been having sex, and again, Louis complicates the situation by talking to Ali.

Like “The New Normal” and “Modern Family,” “Partners” wants to help move TV into relatively unconventional groupings of friends and family. But the stubbornly conventional scripts, the overfamiliar characters, and the old-fashioned, machine-gun comic timing undermine any possibility of freshness. There are worse sitcoms on TV, for sure, but the ones with potential sometimes hurt the most. They lure you in, then leave you flat.